Monte Carlo simulations of ternary solid solutions of key petrological and technological importance.

本项目的重点是建立切合实际的活动-组成模型，并计算多组分固溶体相的温度-压力-组成图，如铝硅酸盐和多数石榴石、含铁和含钾辉石岩、含铕颗粒和碳酸盐。我们还将开发具有有趣技术性能的新材料SiA1ONs中A1/Si和N/O的温度依赖性紊乱模型。这些模型将提高变质岩和地幔岩石学、材料设计和长期核废料处置库安全预测等不同研究领域相平衡计算的准确性。为了完成这项任务，我们将开发一套灵活的软件，专门用于计算机模拟和三元固溶体的热力学建模。该软件将建立在通用实用程序晶格程序（GULP）和我们自己的蒙特卡罗代码上，并将允许模拟一般对称，大小和组成的超级细胞中可交换原子的玻尔兹曼分布。固溶体的热力学混合性质将由蒙特卡罗结果的热力学积分得到。与这些任务并行，我们将开发一个氧化物、氮化物、碳酸盐和molibate的可转移经验原子间电位数据库，与现有数据库相比，该数据库具有更高的准确性。关键词：蒙特卡罗模拟；三元固溶体；

This project is focused on the development of realistic activity-composition models and the calculation of temperature-pressure-composition diagrams of multicomponent solid solution phases such as aluminosilicate and majoritic garnets, Fe3+- and K-bearing omphacitic pyroxenes and Eu-bearing powellites and carbonates. We will also develop models of temperature-dependent disorder of A1/Si and N/O in SiA1ONs - new materials with interesting technological properties. These models will permit to increase accuracy of phase equilibrium calculations in diverse research areas such as metamorphic and mantle petrology, materials design and safety prognosis of long-term nuclear waste repository. To accomplish this tasks we will develop a _exible suite of software dedicated for computer simulations and thermodynamic modelling of ternary solid solutions. The software will be build over the General Utility Lattice Program (GULP) and our own Monte Carlo code and will allow simulation of the Boltzmann distribution of exchangeable atoms in supercells of general symmetry, size and composition. Temperature-dependent thermodynamic mixing properties of solid solution phases will be obtained from the thermodynamic integration of the Monte Carlo results. In parallel with these tasks we will develop a database of transferable empirical interatomic potentials for oxides, nitrides, carbonates and molibdates with a superior accuracy compared to those currently available. Key words: Monte Carlo simulations, ternary solid solutions.